Deep-hole drill



Aug. 31, 1965 R. BERGSTROM DEEP-HOLE DRILL 2 Sheets-Sheet 1 Filed May 3,1963 [NVENTOR ERNST REI DAR BERGSTRb'M 1965 E. R. BERGSTROM 3,203,493

DEEP-HOLE DRILL Filed May 3, 1963 2 Sheets-Sheet 2 INVENTOR ERNST REIDARBERGSTRGM ATTORNEYj United States Patent 3,203,493 DEEP-HOLE DRILL ErnstReidar 'Bergstriim, Stockholm. Sweden, assignor to Stora KopparbergsBergslags Aktiebolag, Falun, Sweden, a joint-stock company of SwedenFiled May 3, 1963. Ser. No. 277,892 7 Claims. (CL 175383) The presentinvention relates to drills of the type called deep-hole drills or gundrills. This type of drill is used (for providing holes with aconsiderable greater length as compared with their diameter.

A severe drawback of hitherto known drills of this type consists in thatit is diflicult or not possible at all to alter or vary the effectivecutting diameter of the drills.

The present invention has for its main object to provide a deep-holedrill the effective diameter of which is easily variable between widelimits.

Another object is to provide simple but effective means for changing theposition of a swingable cutter holder so as to vary the diameter.

A still further object of the invention is to provide positive andreliable mounting of the cutter and its holder in the body of the drill.

It will be seen, that by fixing the cutter holder in arbitrarily chosenpositions the effective diameter of the ldeep-hole drill will be easilyand quickly changed at will. It is likewise easy to tasten the holderand the cutter in the chosen positions.

These and other features of the invention will be disclosed more indetail through the following description, reference being had to theaccompanying drawings, in which:

FIG. 1 is, a side view partly in section, of an embodiment of a drillaccording to the invention.

FIG. 2 is \an end View seen from the left in FIGURE 1.

FIG. 3 is a plan view.

FIG. 4 is a plan view, similar to FIG. 3, of another embodiment.

FIG. '5 is a plan view, similar to FIG. 3 and FIG. 4, of a thirdembodiment.

Reference is first had to the embodiment shown in FIGS. 1-3, where 1designates the body of the drill in question. The body is provided withbuilt-in wear or glide inserts 2.

In accordance with the principle of the present invention the drill hasa cutting plate or blade 3 consisting for instance of so called hardmetal or the like and being rotatable and [fastened in various orselected rotated positions by means of a clamping or holding member 4.

Further in accordance with the principle of the invention the cutter ismounted in a holding member which is swingably connected to the drillrod or body in order to vary the effective cutting diameter of thedrill.

The cutting blade 3 has a circular or polygonal form, and the holdingmember 4 has a circular seat 5 corresponding to the maximum diameter ofthe cutting blade 3. The holding member 4 has further a portion 6projecting over the plate or blade 3. The portion 6 is adapted toprevent the cutting blade from being lifted from its position whendrilling is being performed.

The holding member 4 is clamped against a base surface 7 and/or againstthe cutting blade 3 by means of a screw 8 threaded in the member 4 andarranged in the body 1.

It is thus possible to adjust the cutting blade 3 in arbitraryrotational positions and to fix the same in these positions bytightening the screw 8. When a certain portion of the cutting blade hasbeen worn it is possible to reposition the cutting blade so that a newcutting 3,293,493 Patented Aug. 31, 1965 portion will be used. Thecutting blade is provided with cutting portions all around itscircumference.

As is apparent from FIGUR ES 1 and 2, the cutting blade 3 isfrusto-conical, that is it has a certain clearance angle. This angle maybe such that the under surface 9 of the cutting blade is slightlysloping, for instance 1-10, suitably about 5", upwardly from the basesurface 7 of the holding member 4. The portion 6 is accordinglydiminishing towards the actual cutting portion of the cutting blade.

The recess or seat 5 in the holding member 4 is open forwardly andoutwardly in respect of the drilling direction in correspondence to thestresses occuring in the drilling work, so that the cutting blade willbe automatically pressed into its seat.

The holding member 4 extends partly into a recess 10 in the body 1. Therecess 10 has approximately .the same height as the holding member, andit is adapted to prevent the said member from being lifted fromvitscorrect operating position. The bottom side of the recess is suitablyflush with the base surface 7 tor the member 4.

The member 4 is together with the cutting blade 3 swingable about thescrew 8 which also serves as a fulcrum member. By swinging the parts 3,4 it is possible to vary the effective diameter of the drill within widelimits.

Adjusting and securing of the parts 3, 4 in different diameter positionsis easily carried out by means of an adjusting screw 1 1, which isthreaded into the body 1 and screwab'le into the recess 10 where it hascontact with the member 4.

The holding member 4 is advantageously but not necessarily recessed intothe surface 12 on the body 1, and the said member may be adapted to abutagainst side walls of the recess. A certain play must exist at 1 3 and14 in order to allow for the above mentioned swinging movement. Thescrew 8 may have a sufficient play in the body 1 to allow tor aconsiderable swinging motion as well as for a firm abutment against forinstance the wall 15 of the recess (see FIG. 1).

The very exact, easy and fast adjustment by means of the adjustmentscrew 11 offers previously unknown possibilities in respect of an exactwork, and the possibility or turning or rotating the cutting blade 3allows for maximal use of the cutting blade betore regrinding. The blade3 may have a plurality of positions before its regrinding;

As will be clear from above the invention offers very considerablesaving in respect of time and material.

In the embodiments shown in FIGURES 4 and 5 the cutting blades 16 and17, respectively, have ten and six edges, respectively, and the holdingmembers 18 and 19, respectively, have corresponding seats 20 and 2.1,respectively.

The holding members 18 and 19 have a rounded form at their rear ends 24and 25, respectively, and their corresponding reces-s walls 22 and 23,respectively, have cor responding rounded forms as clearly shown in thefigures. 'Ilhese rounded interoorresponding formations are well adaptedto allow for the swingablity of the holding memher as well as to formeffective lalbutments.

Obviously further embodiments than those here retferred to as examplesare possible within the scope of the invention. Thus, other forms arepossible in respect of the swingable holder and the rotatable cuttingblades. Instead of the regular forms of the cutting blade more or lessirregular polygonal forms may be used. Likewise the holding members maybe varied considerably within the scope of the invention.

I claim:

1. A deep hole drill comprising a drill rod having a longitudinallaterally extending base, a rotatably adjustable blade having aperipheral cutting edge and resting on said base, a holding memberresting on the base in rear of the blade and having a front seat fortheblade conforming to the said edge of the blade, said holding memberhaving a forward portion pnojecting over part of the blade, and meansfor clamping the holding member to said drill rod.

2. A deep-hole drill comprising a drill rod having a longitudinallaterally extending base, a rotatably adjustable blade having aperipheral cutting edge and resting on said base, a holding memberpivotally mounted on the base in rear of the blade and having a frontseat for the blade conforming to the said edge of the blade, saidholding member having a fonward portion projecting over part of theblade, and means for clamping the holding member to said drill rod inpivotal'ly adjusted position with the blade adjustably extendedradially.

3. A deep hole-drill as defined in claim 2, in which said means forclamping the holding member to said drill rod comprises a screw passingthrough the midpoint of said holding member.

4. A deep-hole drill as defined in claim 2, in which the inner end ofsaid base is recessed into said drill rod.

5. A deep-hole drill comprising a drill rod having a one of its ends asubstantially V-shaped depression in the longitudinal periphery thereof,one face' of said depression providing a longitudinal laterallyextending base and the opposite face of said depression being providedwith a recessed area, a 'rotatab-ly adjustable blade having a peripheralcutting edge and resting on said base, a holding member pivotallymounted on the base in the rear of the blade with one of its edges insaid recessed area, said member having a front seat for the bladeconforming to the said edge of the latter, said holding me'mher having aforward portion projecting over part of the blade, and means forclamping the holding member to said dril-l rod in pivotally adjustedposition with the blade adjustably extended radially.

6. A deep-hole drill as defined in claim 5 in which said means forclamping the holding member to said drill rod is a screw in the basepassing through the midpoint of the holding member and the recessed areaback of the screw is deepened to receive the holding member in pivotallyadjusted position.

7. A deelp hole drill as defined in claim 5 in which an adjusting screwin the drill rod engages the edge of the holding member in the recessedarea to hold the member in pivotally adjusted position with the bladeextended.

References Cited by the Examiner UNITED STATES PATENTS 402,394 4/89Brown 175-384 X 522,403 7/94 Calkins 175-398 X 1,468,774 9/ 23 Caldwell175-384 X 1,578,574 3/26 Bateman 175-351 X 1,638,337 8/27 Hutton 175-373X 2,930,588 3/60 Lord 175--410 X BENJAMIN BENDET'I, Examiner.

CHARLES E. OCONNELL, Primary Examiner.

1. A DEEP-HOLE DRILL COMPRISING A DRILL ROD HAVING A LONGITUDINALLATERALLY EXTENDING BASE, A ROTATABLY ADJUSTABLE BLADE HAVING APERIPHERAL CUTTING EDGE AND RESTING ON SAID BASE, A HOLDING MEMBERRESTING ON THE BASE IN REAR OF THE BLADE AND HAVING A FRONT SEAT FOR THEBLADE CONFORMING TO THE SAID EDGE OF THE BLADE, SAID HOLDING MEMBERHAVING A FORWARD PORTION PROJECTING OVER PART OF THE BLADE, AND MEANSFOR CLAMPING THE HOLDING MEMBER TO SAID DRILL ROD.